Condenser construction



' Jan.l24, 1939.* c. M, BLACKBURN 2,144,959

CONDENSER CONSTRUCTION Filed sept. 24, 1937 INVENTOR ATTORNEY man i,... 24, 1939 2,144,959

UNITED STATES PATENT OFFICE CONDENSEB CONSTRUCTION Charles Marvin Blackburn, Jackson Township, `Brown County, Ind., assignor tcl. R.. Mallory Co.,'lnc., Indianapolis, Ind., a corporation of Delaware Application September 24, 1937, Serial No. 165,553

` 16 Claims. (Cl. 175-415) This invention relates to electric condensers Referring to the drawing, Figures l and 2 and the structure thereof. show a condenser can III closed at one end and An object of the invention is to improve the having an annular, internally raised bead I4 near construction of electric condensers. A the open end thereof. 'I'he inside of the can is 5 Another object is to improve the terminal conscored or roughened in the annular area I5 im- 5 struction oi' such condensers. mediately above the bead Il.

Other objects of the invention will be appar- A condenser roll II comprising two or more ent from the following description and accomcondenser electrodes spaced by suitable sheet panying drawing taken in connection with the spacers is inserted within can I l). Flat terminal appended claims. strips I2 and I3 are connected to the condenser `10 The invention comprises the features of conelectrodes and extend toward the mouth of the struction, combination of elements, arrangecan. ment of parts, and methods of manufacture and In the case of a dry electrolytic condenser the operation referred to above or which will be electrodes may be of aluminum foil or other types brought out and exemplied in the disclosure of sheets formed of aluminum or other illm- 15 hereinafter set forth, including the illustrations forming metal and the terminals I2 and I3 may in the drawing. be at strips of the same metal secured to the In the drawing: electrodes so as to provide a good electrical and Figure 1 is an exploded view illustrating a con'- mechanical connection therebetween. Terminal A, denser assembly embodying features of the inconductor I2, for instance, may be an aluminum"'20 vention; wire rolled flat. Terminal I3 may be similarly Figure 2 shows the condenser in assembled formed or may comprise a strip of aluminum state; v foil integral with or attached to its associated Figure 3 is a top view of the completed conelectrode. 2`5 denser assembly; According to the assembly shown in the figures, 25

Figure 4 is a section of the assembly embodythe terminal strip I3 extends upward from one ing a modified vent construction; 0f the outer turns of the condenser roll II along Figure 5 is a longitudinal section through anthe can wall and terminal strip I2 extends upother modified form of condenser; ward from the middle of the roll along the axis Figure 6 is a top view of a further modication; of the can. 30

Figure '7 is a section on the line 'I--1 of Figure 'I'he open end of the can is closed by a com- 6; and posite cap formed oi' three discs IB, I1 and I8, Figure 8 is a section of part of a further modwhich are of substantially the same diameter as iiied form. the inside wall of the can. Discs I6 and I8 are The `present invention is particularly well formed of relatively rigid sheet insulating mate- 35 adapted for the construction of dry electrolytic rial such as sheet Bakelite, other suitable resincondensers. The top vconstruction described proimpregnated ilbre or ceramic. Disc I'I, however, vides an improved sealing means for such conis formed of a soft deformable material such as densers and an improved terminal arrangement unvulcanized rubber, partially vulcanized rubber 40 therefor. The invention is alsosuitable for wet or soft vulcanized rubber or, in some cases, other '10 electrolytic oondensers wherein it provides an efgummy, plastic or elastic materials. Disc I6 is fectively sealed container and a convenient provided with a central rectangular slot I9 of a means for holding a central electrode. cross section adapted to receive terminal strip I2. It is also obvious that the invention can be Rubber disc I1 has a central slit 20 which will used for electrostatic condensers. also permit insertion oi terminal I2. Disc I 8 has 45 While a preferred embodiment of the invena somewhat larger aperture 2| which will accomtion is described herein, it is contemplated that modate terminal strip I2 and also a metal solconsiderable variation may be made in the methdering terminal 22. od of procedure and the construction of parts Terminal 22 comprises a comparatively heavy without departing from the spirit of the invenstrip of metal somewhat wider than terminal 50 tion. In the following description and in the strip I2. Terminal 22 is bent at right angles at claims, parts will be identified by specific names a point near one of its ends to provide an an- -for convenience, but they are intended to be as choring portion 23 which is disposed between generic in their application to Similar parts as discs I'I and I8 with the main body of terminal the art Will permit. 22 extending out through the aperture 2| in disc 55 I8. A pair of ears 24 are struck up from the edges of terminal 22 just above the surface of disc I8 and terminal strip I2 is disposed against the surface of terminal 22 between the ears 24. A hole 25 is punched in the free end of terminal 22 to aid in making connections thereto and a small hole 26 is punched in the portion of terminal 22 between the ears 24.

In assembling the condenser the condenser roll II is i'lrst inserted in the can with its terminals I2 and I3 extending out of the mouth of the can as described. Disc IG is then placed in the mouth of the can with terminal I2 extending through its central slot I9 and terminal I3 pressed against the wall of the can by the edge of the disc. Disc I1 is then inserted directly on top of disc I6 with the terminal I2 received in its central'slot 20. Terminal 22 is inserted in top disc I8 as described above after which disc I8 is placed on top of disc I1 with terminal strip I2 passing through the disc and lying against the face of terminal 22 between the two ears 24.

'I'he top edge of can I0 is then spun over the top surface of disc I8, as shown in Figure 2, thereby pressing the three discs tightly together between bead III and the spun end of the can. This pressure causes soft rubber disc I1 to expand against the inside wall of can I and against the terminal strip I2, thereby effectively sealing the inside of the can. Terminal strip I3 is rmly pressed against the wall of the can by this operation and due to the scoring I on the can wall a good electrical connection is made between terminal I3 and the canAIII. Finally, the ears 24 of terminal 22 are bent over on top of terminal strip I2 and a portion of the material of strip I2 is punched into small hole 26 in terminal 22. This forms a good electrical andmechanical connection between the terminal strip I2 and terminal 22 outside of the sealed portion of the can. These last two steps are seen most clearly by reference to Figures 3 and 4.

The intermediate layer I1 of rubber or the like, due to its deformability and softness is expanded against the can wall and the terminal, as previously described to effect a seal. In most cases, particularly if unvulcanized or partly vulcanized rubber is used the layer I1 is permanently deformed and by aging by time alone at room. ternperature or at the usual operating temperature of the condenser the material will cure in its deformed position and effect a permanent seal of the condenser without the necessity of further maintaining pressure upon it. The material may also adhere to the can wall and the electrodes.

Instead of inside bead I4 in the can, other means can be provided to support the discs such as. for instance, point indents in the can, an outside bead providing a corresponding annular groove in the inner wall into which the disc can extend.. or an internal sleeve of metal, libre,

,cardboard or a resin materialresting on the bottom of the can and extending to a point where its upper can support the discs.

In some applications it may be necessary to provide a pressure release valve or vent in the can top. One form oi' vent is shown in Figures 1 and 2 and is formed by punching three aligned holes 21, 28 and 29 in discs I6, I1 and I8. A thin rubber membrane 3U is then laid between discs I1 and I8 to close the passageway formed by the aligned holes and pinhole 3| is punched in the center of the membrane 30. The membrane 3I thereby seals the opening but allows gases to escape when any substantial pressure develops.

Another form of sealing arrangement is shown in Figure 4. In this embodiment, instead of providing a rubber membrane, the passageway provided by aligned holes 21, 28 and 29 is stopped up with a small globule of wax or other plastic material 32. Should excessive pressure develop within the condenser, the wax particle will be blown out, thereby relieving the pressure.

Figure 5 shows another form of terminal arrangement. In this form the central terminal of condenser roll II comprises a round wire 33 which extends out through suitable holes in the centers of discs I6, I1 and I8. Threaded metal bushing 34 is tted into a central opening in top disc I8 and has a ange 35 integral with its inner end and disposed between discs I1v and I8. Terminal wire 33 extends through the center of bushing 34. The bushing is split longitudinally in its threaded region and tapered slightly toward its outer end. A nut 36 is screwed on to the bushing and tightened down against the top of disc I8, thereby contracting the bushing 34 on to wire 33. The wire 33 may then be clipped off above the end of bushing 34. This provides a threaded terminal.

Also shown in Figure 5 is a further form of vent arrangement which is made by simply providing aligned holes 21 and29 in the Bakelite discs I6 and I8 and after the assembly is complete punching a pin-hole 41 in the rubber disc I1.

Figure 5 also illustrates the use of an additional soft rubber ring 31 on the top of disc I8 as a further sealing means. Obviously this expedient can also be used in the other forms described.

In some instances it is desired to have a threaded insulating top on the condenser. Such an arrangement is shown in Figures 6 and 7 wherein molded top 39 of insulating material such asBakelite or ceramic is placed on top of the disc assembly. In this case the top disc I8 may be replaced by disc 38 of smaller diameter.

Threaded top 39 comprises a threaded cylindrical portion closed at one end with a plane end wall 40 and having an external flange 4I at the other end. Flange 4I rests against the top of disc 38, the edge of can I0' being spun over the top edge of the flange. vThe terminals 42 and 43 are generally similar in construction to terminalj22 but are somewhat longer so that they will extend up through suitable slots in the end wall 4I) of the bushing 39. The condenser terminal strips I2 and I3 are secured to terminals 22 yand 23 within the chamber' formed inside o f threaded cap 39 so that only the ends of terminals 42 and 43 are exposed.

Figure 8 illustrates a condenser construction in which three terminals 44, 454and 48 are provided in the can top, all of which are insulated from the can III.

It will be obvious that any desired number of terminals can be provided with any of the constructions illustrated and that the venting arrangements may or may not be used, as required. It is also contemplated that a metal tube can be used instead of can II! and both ends be sealed by the sealing discs as herein described.

Among other advantages the'present invention providesl a simple and economical' sealing means readily adapted to a variety of terminal and vent arrangements and suited for condensers of the dry electrolytic, wet electrolytic and elec-- trostatic type.

The construction can be made of standard maly formed or molded parte.

An e cellent and permanent seal is obtainable n by the` invention,

While the present invention, as to its objects and advantages, has been described herein as carried out in specific embodiments thereof, itis not desired to be limited thereby but it is intended to cover the invention broadly within the spirit and scope of the appended claims.

What is claimed is:

l. A condenser comprising a metal can, a con'` denser roll therein, an internally raised bead near the open end of sai' vcan and a laminated sealing cap for said can Vccmprising a pressure deformable central lamina and relatively stiff substantially undeformable laminae on both sides thereof, said cap fitting snugly within the open end of said can and resting on said bead, the end of said can being spun over the edge oi' said cap, and at least one terminal connected to said condenser roll and passing through an opening in said cap.

2. A condenser comprising a metal can, a condenser roll therein, internal shoulder means near the open end of said can and a laminated sealing cap for said can comprising a soft rubber central lamina and Bakelite laminae covering practically all of both sides thereof,v said. cap fitting snugly within the open end of said can and resting on said shoulder, the end of said can being spun over the edge of said cap, and at least one termi nal connected to said condenser roll and passing through an opening in said cap.

3. A condenser comprising a metal can, condenser electrodes therein and a cap sealing the open end of said can, vsaid cap comprising a stack of at least three discs, the middle disc being of soft pressure deformable material and the other two discs being of stiff relatively nondeformable material, a terminal strip connected to one of said electrodes and extending through said cap and a terminal connected to said strip, said terminal comprising an anchoring portion wedged between said soft layer and the outer one of said stiff layers anda terminal portion extending out through said outer layer, said can having portions exertingpressure on said disc stack to compress said middle disc between said stlif discs. C

4. A condenser comprising a metal can, condenser electrodes therein, and sealing means for the end of4 said can comprising at least three discs superimposed one upon the other, the middle one of said three discs being formed of pressure deformable material and the other two of said discs being of relatively stiil' hard material, and at least one terminal for one of said condenser electrodes passing through said discs and a threaded. cap of insulating material having a iiange thereon resting on the outer one of said discs, said terminal passing through said cap.

' 5. A condenser comprising a metal can, a condenser roll therein, internal shoulder means near the open end of said can and a laminated sealing cap for said can comprising a curable rubber Ycentral lamina and Bakelite laminae covering practically all of both sides thereof, said cap fitting snugly within the open end of said can and resting on said shoulder, the end of said can being spu'n over the edge of said cap, and at least one terminal connected to said condenser roll and passing through an opening in said cap.

6. A condenser comprising a r'netal can, condenser electrodes therein, and sealing means for the end of said can comprising at least three aum specialdiscs superimposed one upon ther other,

middle oneof said three discs being formed of' the pressure deformable material and the other two of said discs being of relatively stii'l hard material, and at least one terminal for one of said condenser electrodes passing through said discs, and another terminal for said electrodes comprising a strip of metal wedged between said discs and thevinside wall oi' said can, said can being roughened in the region of contact with said terminal.

7. A condenser comprising a cylindrical metal can, a condenser electrode assembly therein, an

' internal shoulder near the open end of said can and a laminated sealing cap for said can comprising a central lamina of pressure deformable material and relatively stifi substantially undetermable laminae on both sides thereof, said cap ntting snugly within the open end oi' said can and resting on said shoulder, the end of said can being spun over the edge of said cap, and at least one terminal connected to said electrode assembly and passing through an opening in said cap, said pressure deformable lamina being spread by the pressure supplied by the spun-over edge of said can so as to press against said terminal and also press against said can wall as a seal.

8. A condenser comprising a cylindrical metal can, a condenser electrode assembly therein, an internal shoulder near the open end of said can and a laminated sealing cap for said can comprising a central lamina of pressure deformable soft rubber and relatively stiii' substantially undeformable Bakelite laminae on .both sides thereof, said cap yfitting snugly within the open end of said can and resting on said shoulder, the end of said can being spun over the edge of said cap, and at least one terminal connected to said electrode assembly and passing through an opening in said cap, said pressure deformable rubber lamina being spread by the -pressure supplied by the spun-over edge of said can so as to press against said terminal and also press against said can wall as a seal.

9. yA condenser comprising a cylindrical metal can, a condenser electrode assembly therein, an internal shoulder near the open end of said can and a laminated sealing cap for said can comprising a central lamina of pressure deformable material and relatively stiff substantially undeformable laminae on both sides thereof, said cap fitting snugly within the open end of said can and resting on said shoulder, the end of said can being spun over the edge of said cap, and at least one terminal strip connected to said electrode assembly and passing through openings in said three discs, and a terminal lug comprising a strip of sheet metal bent to provide an anchoring area at one end angularly disposed with respect to the remainder of the body of said strip, said terminal lug passing through the same opening as said terminal strip in the outermost of said three discs with said anchoring area wedged between sa'id outermost disc and said central deformable lamina and the body of said strip projecting beyond the end ofthe can, said terminal strip being secured to said terminal lug outside said cap, and said pressure deformable lamina pressing against said terminal strip and the anchoring area of said terminal lug so as to eilect a seal where the terminal passes through the cap.

10. A condenser comprising a metal can, a condenser roll therein, an internally raised bead near' said cap i'itting snugly within the open end of said can and resting on said bead, the end of said can being spun over the Vedge oi' said cap, and at least one terminal connected to said condenser roll and passing through an opening in said cap.

I11. A condenser comprising a can. condenser electrodes therein, internal shoulder means near the open end of said can, and sealing means for said can comprising a cap of at least three laminae superimposed one upon the other, the middle of said laminae being formed of a pressure deformable material having an adhesive surface and the other laminae being of relatively stiff hard material, at least one terminal for said condenser electrodes passing through said cap, said cap resting on said shoulder means and portions of said can applying pressure to the outer face of said cap.

12. A condenser comprising a can, condenser electrodes therein, internal shoulder means near the open end of said can, and sealing vmeans for said can comprising a cap of at least three laminae superimposed one upon the other, the middle of said laminae being formed of at least partially unvulcanized soft rubber and the other laminae being of relatively stiff hard insulating material, at least one terminal for said condenser electrodes passing through said cap, said cap resting on said shoulder means and portions of said can applying pressure to the outer face of said cap. s

13. A condenser comprising a can, condenser electrodes therein, internal shoulder means near the open end of said can, and sealing means for said can comprising, a cap of at least three laminae superimposed one upon the-other, the middle of said laminae being formed of pressure vdeformable sealing vmaterial and ythe other laminae being of relatively stift hard material, said cap resting on said shoulder` means and other portions of said can applying pressure to the outer surface of said cap, at least one terminal for said condenser electrodes passing through said cap and being formed of difiiculty soiderable metal and a soldering lug anchored in said cap and'electrically and mechanically connected to said terminal externally to the sealed portionof said can.

14. A condenser comprising a metal can. a conarcane denser roll therein, internal shoulder means near the open end of said can and a'laminated cap for said can comprising a circular soft rubber central lamina and stift circular laminae on both sides thereof, allof said laminae being of substantially the same outside diameter, said diameter being y substantially that of the interior of said can above said shoulder, said cap Iiltting snugly within the open end of said can and resting on said shoulder, the end of said can being spun over the edge of said cap and pressing against the top surface of the outer stil! laminae, and at least one terminal connectedto said condenser roll and passing through said cap. l

15. A condensercomprising a metal can, a condenser roll therein, internal shoulder means near the open end of said can and a laminated cap for said can comprising a circular central lamina of pressure-deformable material and stiff' circular laminae on both sides thereof, all of said laminae being of substantially the same outside diameter, said diameter being substantially that of the interior of said can above said shoulder, said cap fitting snugly within the open end of said can and ,resting on said shoulder, the end of said can being spun over the edge of said cap and pressing against the top surface of the outer stiil 1amina,'and at least one terminal connected to said condenser roll and passing through said cap.

16.' A condenser comprising a metal can, a condenser roll therein, internal shoulder means near the open end of said can and a laminated cap for said can comprising a circular soft rubber central lamina and stiil circular laminae on both sides thereof, all of said laminae being of substantially the same outside diameter. said diameter being substantially that of the interior of said can above said shoulder, said cap tting snugly within the open end of said can and resting on said shoulder, the end of said can being spun over the edge of said cap and pressing against the top surface of the outer stiff lamina, an L-shaped terminal lug having an anchoring portion secured to said cap and terminal portion projecting outward from saidv cap, and a terminal connection between said condenser roll and lsaid lug. 

